Flask



FIG. 1 is a perspective view of a flask, showing the new design;

FIG. 2 is an exploded perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right-side elevational view thereof, the left-sideelevational view being a mirror image thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

What is claimed is the ornamental design for a flask, as shown anddescribed.